[Periosteal bone formation in Crohn's disease].

Crohn's disease not only affects the gastrointestinal tract but also causes skeletal complications. Arthritis and ankylosing spondylitis are among the best known of these, while periostal new bone formation in patients with Crohn's disease is rare. A report is presented on a patient who developed this complication after Crohn's disease of many year's standing.